In more detail
In reflexive thematic analysis the researcher's subjectivity is treated as a resource for analysis rather than a bias to be removed. Reflexivity is the practice of noticing and recording how that subjectivity works: what the researcher brings, what they expected, and why they made the choices they did.
Many researchers keep a reflexive journal alongside their coding, and describe their position in the method section. Recording why a theme was reshaped, or why two codes were joined, is part of the same practice.
In Themescape
The notes column of the Data tab is kept for your own memos and ignored by the viewer, and a connection carries a note saying why you linked two themes or codes. Neither is a substitute for a reflexive journal, but both keep reasoning beside the data.
Where to read more
Braun, V., & Clarke, V. (2022). Thematic analysis: A practical guide. SAGE.