I'm not sure I understand.

1) Do you want a list of games that have bundle discounts?
If so, Filters -> Price -> has extra discount if bundled -> True.
Currently 255 such games.

2) Do you want a list of games that have bundle discounts as part of the current sale (as opposed to everyday bundle discounts)?
If so, use the filter from (1) and add a second filter:
Filters -> Price -> is currently on sale -> True.
Currently 31 such games.

3) Do you want something else?
Please elaborate.

Let me clear it. Consider there is a game and It was discounted 3 times. 50% and 75% as an individual game/sale, and 80% as a bundle.
Is there any way to see only individual discounts? For above example, I just want to see 50% and 75%. I want to remove discounted bundles from the search result.
Hope this description clarifies my above post.

It's the default. You cannot perform numeric searches on bundle discounts, only on individual discounts.
The filtering for bundle discount is only basic (has it now, had it in the past), not numeric.

Thanks. :)

ANNOUNCEMENT:
Version 6.5.1 has been released with the following features:

* Improved the collection of "Ungiftable" (i.e. cannot be bought as a gift) information
*** Note: Until now, MaGog checked all games for ungiftable status only in two countries (US and Russia); it continues to do the same, but...
*** Note: If a game is found to be ungiftable in the US (assumed to be ungiftable worldwide), all other known regions are checked as well to see if there are any exceptions.
*** Note: If a game is found to be ungiftable in Russia (assumed to be ungiftable in RU/UA/UZ), the UA and UZ regions are checked as well to see if there are any exceptions.
*** Note: The exceptions found as a result of this new algorithm are:
*** Note: SOMA cannot be bought as a gift only in Russia (yet can be bought in Ukraine and the other nine heavily-discounted ex-Soviet countries).
*** Note: Witcher 3: Wild Hunt, The - Game + Expansion Pass cannot be bought as a gift worldwide, except in The United Kingdom (unlike other Witcher 3 items).

Those Gogmix lists are useful, good addition mrkgnao & creators. : )

Perhaps I'm doing something wrong, but is there a way to hide owned games when doing a search, after having done the "GET From GOG"?

I knew it must be something obvious I'm overlooking. Cheers.

ANNOUNCEMENT:
Version 6.5.2 has been released with the following features:

* Added PaterAlf's "Games that got additional content for free after release" GOG mix to the Gogmixopedia display and filter

Thank you! Exactly what I needed to get active again and update my GOGmix. Still not complete yet, but I added several new games.

Is it possible to somehow search for DLCs for games that are tagged as owned?

Unfortunately, no.

MaGog has practically no concept of relations between items.

I have been thinking recently about adding the concepts of a "pack" (a single game composed of more than one entry, e.g. base game + DLC 1 + DLC 2 + deluxe edition) and a "series" (multiple games/packs belonging to the same series, e.g. Witcher), but the problem is that the relationship information needs to be managed manually every time GOG adds a game (or changes a game ID) and that's a pain, as I don't see how this can be fully and consistently retrieved from GOG's website.

Note

For some reason, since this morning GOG is preventing MaGog from collecting bundle discount information (using Grimwerk's Method™). It might be some server load alleviation measure, or it might be something else.

Anyhow, this means that the bundle discount percentages presented on MaGog are currently incorrect (they reflect yesterday's state, not today's). All other metrics (e.g. prices, regular discounts, etc.) should be ok.

I'll continue investigating it, but for now it's mostly a waiting game.

Not sure whether it helps at all, but if you go into the console on a games page and run:

gogData.gameProductSeriesData

It gives you the list of games that come up under the "BUY SERIES – COMPLETE IT" header...

But I presume the problem may be more to do with retrieving that data without having to visit each individual game's page (I assume you get most of your data through GoG's own Ajax methods and URLs)

The series data does seem to be attached to the product data as well, so it could potentially be pulled from anywhere a game is listed (for example the account page or the /games page) with just a little more work if that would be better...

Unfortunately it doesn't seem to differentiate between other games in the series and DLC.. though it's probably possible to do that on your end? (You could presumably filter results by DLC that is a part of a series to retrieve a game's DLC, though it might return any DLC for any game in said series that way)

Let me know if that is any help and I'll poke about further...