There are some fascinating discussions of similarities between biblical and Hittite material concerning some rituals and concepts/practices regarding purity. Feder in Blood Expiation in the Hebrew Bible notably argues for a connection between the Hittite zurki rite and the biblical Ḥaṭṭaʾt/”sin offering”.

1. Feder’s article, “Behind the Scenes of a Priestly Polemic: Leviticus 14 and its Extra-Biblical Parallels” notably argues that the passage concerning house ṣara‛at partly a polemical reaction to other rituals, notably Hittite (see the “House Fungus” section starting on p9).
2. Milgrom in his seminal Anchor Bible commentary on Leviticus also draws some comparisons with Hittite material, notably concerning the “day of purgation” and so-called “scapegoat ritual” in Lev 16.

Finally, some scholars argue for an influence of Hittite treaties on the structure of some parts of Deuteronomy, notably Deut. 28 and its series of blessings and (longer) graphic curses. As well as some scholars proposing a closer relationship with the Esarhaddon Succession Treaty and more generally neo-Assyrian treaties.

https://books.google.fr/books/about/Deuteronomy_28_and_the_Aramaic_Curse_Tra.html?id=a7Q1DwAAQBAJ&source=kp_book_description&redir_esc=y

Concerning Hittite influence, Richard Hess argues for a similarity between 2 Sam 7 and some Hittite practices and treaties:

1. He also briefly talks about indirect Hittite influence when discussing parallels between some biblical texts and rituals from Emar (a “Syro-Hittite” city destroyed in the 12th cent. BCE, where among other cultural “influences” the Hittite one was manifest).
2. https://www.degruyter.com/document/doi/10.1515/9781646020676-009/html?lang=en Joshua Berman also argues for Hittite influences.