If I want to make an item set for Jax, I shouldn't see items available only on Viktor or GP. And I shouldn't see ranged weps like Runaan's either. If I want to make an item set for ARAM, I shouldn't see items like Guardian's Angel in the list, which are not available in ARAM. Please :D
LoomberFoot1 votesAlready can do that look on the right while making it a tab called champions and maps.
GaleWinUnleashed1 votesI'm not 100% sure what you're saying. Item sets already allow you to customize a build for any map and/or champion.
Is your issue the fact that, when building a set for Jax, Viktor's Hex Cores still show up in the list as you're putting it together? Those champion-specific items are always going to show up at the top of the list unless your filter it. You can always sort by stats, or simply search the item names directly.
AdeBug1 votesthat's what I'm saying, the filter is not per champ or map, although I'm selecting a set for a champ or map.