in ESE (JetBlue) is there a way to limit a search with multiple keys?

Question

In Extensbile Strage Engine (ESE/JetBlue) I've got a table that contains data I'd like to locate using two indexes

assuming that each row has three integers X, Y, and Z. I'd like to quickly locate all the rows where X=10 and Y=20 (for example)

the resulting set would contain all the entries where X=10, Y=20, and Z= whever Z happened to be

is this possible?

the sequence of

JetSetCurrentIndex(), JetMakeKey(), JetSeek(), and JetMove() confuse me. i'm not 100% this is even possible without searching for X=10 and then filtering all values where Y!=20 myself?

thanks!