I need to create a saved search that will return all GL activity related to a work order. But I’m not sure where to start. Can I do that by going after a record type on transaction? or is this really multiple searches?

Well since work orders arent posting transactions, you need transactions where the applying or applied to transaction is work order. Something like

Posting is T

and

Applying transaction fields... type is Work Order

or

Applied to Transaction fields... type is Work Order

interesting