This description accurately describes what you are trying to determine in:

A discipline is potentially relevant if the problem falls within its research
domain but it is not known whether the discipline’s experts have written about the
problem. If they have not (and the literature search will reveal this), then the
discipline is not relevant (although more advanced researchers might still consider
such a discipline). If the discipline’s experts have produced one or more insights into
the problem, then the discipline is relevant.

a. Step 4 – Conduct the Literature Review
b. Step 3 – Identify Relevant Disciplines
c. Step 2 – Justify an Interdisciplinary Response
d. Step 1 – Define the Problem or State the Research Question

b. Step 3 – Identify Relevant Disciplines