I have a 'DeptNumber' SP List (below).

I have a Power App with Gallery1.
When a 'Principal' views Gallery1 I'd like the Gallery to be filtered by whether the DeptNo. appears in the 'Title' column of
the 'DeptNumber' SP List.
I am setting a variable at OnStart -
Set(varDepartmentNumber, LookUp(DepartmentCodesCollection, DeptDescription = UserDepartmentFld.Text,Title));
Goal: If the viewer is a 'Principal' filter Gallery1 to show only items where the Department Number is in the Title column of the SP List.
If(IsBlank(CategorySearchComboBox.Selected.Value) && UserJobTitleLbl.Text = "Principal" &&
varDepartmentNumber,
SortByColumns(Filter(LessonCollection,
Status.Value = "Pending Teacher Approval" ||
Status.Value = "Request for More Information" ||
Status.Value = "Lesson Under Teacher Review"),"MeetingDate",SortOrder.Descending))