create new table with partial columns from another table in dax

I have a table with N Columns where I have (among others) the following columns and conditions
A) There are 3 executing/managing sites (IN-HOUSE)
B) There are 4 outsourcing sites (OFFSHORE)
C) For every offshore Project, there must always be an IN-HOUSEManaging site

1) DEPARTMENT - Contains Coding/Managing site (Either in-house or Offshore) - IN-HOUSE_A,IN-HOUSE_B, IN-HOUSE_C, OFFSHORE_A, OFFSHORE_B, OFFSHORE_C, OFFSHORE_D
2) Project_Name
3) Plan_Date

a) If the project is being Managed and Coded 100% in-house in one SINGLE SITE, then there is just ONE record for that PROJECT in that DEPARTMENT in a certain PLAN_DATE, e.g.: DEPARTMENT = IN-HOUSE_A - (B or C)
b) If the project is being Managed and Coded 100% in-house in more than one Executing Site, then there is ONE record for each Executing Site in the DEPARTMENT column for that PROJECT in a certain PLAN_DATE (in this case, it could be considered as separate projects since Budgeting is done at the Executing/Managing Site level)
c) If a Project is sent offshore (it can be sent to 1 or more off-shore Coding sites), there would be two or more records
i. One record with DEPARTMENT = "IN-HOUSE_A" -(B or C)
ii. One record with DEPARTMENT = "OFFSHORE_A" -(B, C or D) for each off-shore site where code is being done

I want to find a way in DAX (or Power Query) to add a CUSTOM COLUMN in that table to indicate the Managing Site for each outsourced project for easier reporting and filtering, e.g.:
a) Cost plan by Executing site for 100% managed projects
b) Cost Plan by Coding site for outsourced projects
c) Cost Plan by Managing Site-Coding Site

NOTES:
To detect Managing Site, I was thinking on locate DUPLICATES (PROJECT_DATE + PLAN_DATE) then:
i. locate the DEPARTMENT value for record containing DEPARTMENT = IN-HOUSE_X (A, B, or C) value
ii. Locate it's associated records (with same PROJECT_DATE + PLAN_DATE) but DEPARTMENT = OFFSHORE_X (A, B, or C) and copy the IN-HOUSE department from the previous record to the Custom column, understanding that can be 1 or more offshore records||
iii. For unique records, I'd add a custom label (e.g.: "100% IN-HOUSE") or leave it blank in that Custom column

I can't change the design on the table since it comes from a C.A. Clarity PPM feed