Not sure if this is already fixed in a later version, but I've got Data Studio 18.104.22.168, connecting to a DB2 LUW 10.5 FP3 (installed on Windows). This isn't a major issue, I'm just reporting it like a good db2 user. :)
The basic issue is that when I create a filter on the Table Listing, this also affects the listings of the indexes, whereas I would have assumed they would be independent. So, if I have a filter on tables where the name starts with "ABC", then if I switch over to the index view, the indexes listed are only for tables whose names begin with "ABC", even though there is no filter defined for indexes.
I do notice that 22.214.171.124 is now the latest - maybe I need to upgrade.