You could always just have them asking around on the black market, make a check for it. Or maybe the piece of the puzzle they do possess (or its previous owner) has a clue to the whereabouts of the next piece? Or consult an expert. Doctor Aphra would never betray them.

Another entity with a clue in possession could also be seeking the other pieces of the puzzle... in such an instance, a piece of the puzzle could come to them. And of course, in this franchise, one of the “coordinates” might well be hidden in a droid.

There is rumored to be an ice world with an ancient vault where a lot of old Mandalorian stuff was stashed (weapons, Beskar, Basilisks, etc.), but no one has been able to find it.

According to the rumor, the Mandalorian who had the complete location split it into its four component parts and entrusted one to each of his children. Three of them lost it in various ways, the fourth was passed down through the generations until now. A descendant of that Mandalorian brought it to the attention of someone in Bo Katan’s circle, which started this whole mission in the first place. He claims that his piece is the latitude of a grid square and that the other fragments would give a full picture: column, row, and longitude, all of which together would point to a square parsec inside a grid square. It’s a big area to search, but shouldn’t prove too hard.

The location of the other fragments is a mystery, but the man who turned over the fragment claims that one of the fragments made it onto the black market. At some point, one of his family members attempted to acquire it from a black marketeer, but failed when he sold the information to someone else first.

He says that he thinks they might be able to find the fragment if they do some digging, and if they find the one fragment, it may lead them to others.

The other information fragments:

The Column is in the hands of a Yarkora explorer who has become stymied in his search. If he catches wind of the PCs efforts, he may contact them and offer to sell it to them. He is actually hoping that they will be able to find it for him, or put him onto the trail, so that he can swoop in and grab it all for himself.

Doctor Aphra has come into possession of the Row, and is desperate to find the other pieces. She may try to get the PCs’ piece, or possibly offer to join forces, only to betray them. Possibly multiple times.

Doctor Aphra has (or acquires during the course of the campaign) an old datapad that served as the journal of an old xenoarchaeologist who was also searching for the location of the vault. According to the journal, the xenoarchaeologist’s droid has the Longitude in his memory banks, but the location of the droid is a mystery. However, the end location of the explorer is known. He died on Licha In, a world in the Gree Enclave, and his datapad was sold to Aphra by an archaeologist who knew Aphra and figured she’d follow up on the notes in it, as treasure hunts are more her thing and he was busy with his research on Licha In. She believes that her acquaintance (she doesn’t think they can really be called friends) might be in possession of the droid, or at least may possess the information. The complication is that Aphra betrayed him and stole some valuable artifacts from him, and he is (obviously) not too happy about it.