Category dropdown on edit entries page

The category dropdown, even tho it now includes search, is alot less usefull now.

We have a web shop with about 300 categories and 3000 or so products. Categories are organized in 3 category groups, one group has 4 leves. When category dropdown is opened, categories are just listed, ordered by category id.

Even if we disregard the fact that, if you try to type something into “filter categories” field it causes CP to hang with unresponsive scrop error, the usability of it is pretty limited.

Several categories have a similar name, and some categories are just set of dimensions such as WT400, WT450 and can appear in several parent categories. Withouit exactly knowing category name its dificult find it, since by looking at the list in the dropdown, you have no idea what its parent category is.

If we can atleast get categories to get separated by group, and indented depending on their parent as it was in EE2, that would be great.