Within the Law Bod, depending again on the nature & scope of your research, you may well be directed to all floors in the Library.
If your interest is philosophical/theoretical in whole or in part: monographs beginning Jurisp are on Level 2.
If your research has a jurisdictional focus: UK. Australian, Canadian, Irish, NZ and USA works are on Level 2 in the K shelfmark section. European Union law (shelf mark Euro Comm) and the laws of the member states are on Level 3. Remaining jurisdictions on Level 1.
Comparatve studies, shelf marks starting General, are on Level 2.
International Human Rights works, shelf marks starting Internat, are on Level 3.
Subject searches to try in SOLO include the following:
Religion and state
Church and state
Religious minorities -- Legal status, laws, etc
Cults -- Law and legislation
Religious institutions -- Law and legislation
Discrimination -- law and legislation
Religious discrimination -- Law and legislation
Religion in the workplace Law and legislation
Equality -- Religious Aspects
Cultural pluralism -- Great Britain
Comparative religious law
Freedom of religion (International law)
Freedom of religion -- History
Below are some examples of books within this topic - chosen really to demonstrate how each is available in a different Bodleian Libraries, and that the last one would need to be requested from the Stacks.
If you notice books you would like to read are in the Closed Stacks, sign into SOLO and you by making a Hold Request you can ask for the book to be delivered to the Bodleian Reading Room of your choice. The link immediately below goes into this procedure in further detail - and any Bodleian Librarian is happy to explain this procedure - so please do ask when next you are in the Library.