Swan (2005) explains that phonology is the study of the...

Swan (2005) explains that phonology is the study of the sound systems of languages, particularly how sounds function to convey meaning. This involves analyzing the arrangement and patterns of sounds (phonemes) in a particular language.
Which phonological process is responsible for the phenomenon where the sound /t/ is pronounced as [ʧ] (a voiceless postalveolar affricate) in the word "nature" due to the influence of the following /ʊr/?