Minion at Town Hall 8: max level 4. At Town Hall 18 the cap is level 14. It unlocks at Town Hall 7. Max level per Town Hall: TH7 2, TH8 4, TH9 5, TH10 6, TH11 7, TH12 8, TH13 9, TH14 10, TH15 11, TH16 12, TH17 13, TH18 14.
Tap a Town Hall to open this item there. Dashed: not available at that Town Hall yet.