Hook: Floor Large (Purple Square)The Arrangement: Tribal Camp decoration fits into a large purple square floor hook.
How to Get an Arrangement: Tribal Camp Decoration
Cartel Pack Decorations
The Arrangement: Tribal Camp decoration can be dropped from Constable's Stronghold Packs, which were released on the Cartel Market and bought with Cartel Coins. Cartel Packs, including the Constable's Stronghold Pack, include a random selection of items from the Constable's Stronghold collection of items. You aren't guaranteed to get an Arrangement: Tribal Camp decoration from a Constable's Stronghold Pack, but it is one of the few ways to get an Arrangement: Tribal Camp deco apart from buying it on the GTN from another player.
If you're looking to get a Arrangement: Tribal Camp, the easiest way to get it is to head to the Galactic Trade Network (GTN) in SWTOR and buy it with credits from another player. If it's very rare and not available on the Cartel Market, you could try buying from the GTN and hope you get it.