Hi NetSuite professionals, Can anyone please help me here to bring this highlighted value (Accounting Book) into Transaction saved search? I tried 1. under Applying Transaction Fields... but didn't find any correct one. 2. with Formulae field as well but still no luck.

right click on this page, view page source. search "secondary book". next to it, there should be the field id. that should give you a pointer what to look for.

There's a Multi-Book Accounting join to transaction searches that contains that info. Or used to be anyway. I haven't bee in a MB environment in a long time.