How to get list of values from another column that has another value found in its row.

[Jpaulsen]

Hello. 

I was wondering if someone can point me in the right direction here. These formula's are a little different the excel's. So I really frustrated on make a these formulas work. 

First formula is Select(equipment[unit], ( [_thisrow].[type of filter] = [Part Number].[type of filter]), True) it works but it pulls all the units that don't have the "part number" in its same row of information. I like to only get the units that use this part number. 

Second is. I lost on complete my formal in my valid if that if the value is not there that a I can input a new value. 

IFS(
[Type of Filter] = "Engine Oil Filter",
UNIQUE(equipment[Engine Oil Filter]),

[Type of Filter] = "Fuel Filter",
UNIQUE(equipment[Fuel Filter]),

[Type of Filter] = "Water Separator Filter",
UNIQUE(equipment[Water Separator Filter]),

)

Third with the second formula, how would I able to include a list and/or select?

Thank you so much in advance.