Have a tab that shows you all dlc not owned

Same as above. With an exclusion filter to omit certain games

SnowPixii You mean DLCs for specified game or for all games you have in your collection?

rob006 correct 💯

There are already views with DLCs list for specified game, where you can hide owned and ignored DLCs: https://gg.deals/game/total-war-warhammer-iii/dlcs/?hideIgnored=1&hideOwned=1

For single view with all missing DLCs for all owned games we already have existing feature request, so please vote here: Filter that shows missing DLC for owned games