The full title of this work is Gazetteer of Parish and Civil Jurisdictions in East and West Prussia compiled by Stephen Samuel Barthel. This work is based on Gemeindelexicon für das Königreich Preußen, published in 1905.
The gazetteer shows the province, East or West Prussia, as well as the locality of the local protestant church, catholic church, and civil records office. For example, if I wanted to find the protestant records for Liebenau (Gostycyn in Polish), I would choose the one in West Prussia in the district of Tuchel (Tuchola in Polish). The gazetteer tells me the protestant records would be in Bagnitz. To see if there are filmed records from Bagnitz, I would check in the Locality Catalog of the LDS for GERMANY, PREUßEN, WESTPREUßEN, BAGNITZ.