Loading Data From Staging Table to Parent and child Tables

Any idea?
I tried with different way but getting some errors. Problem is when i try to load Data from StagingTbl with another two table's PK value then my any logic is not working. Any help will be great help for me as i have to load into another table also and that table contains five Table's PK value along with
StagingTbl's fields.

My query is: The First Two insert works fine for DC and FC
I tried this way"
INSERT INTO [dbo].[DCName]
([DCatID], [FCatID], DNameCat, DWebName)
SELECT
(SELECT [DCID] FROM dbo.[DC] WHERE [DC].[DCName] = [dbo].[ DM ].[DCName]) ,
(SELECT [FCID] FROM [FC] WHERE [FC].[FCName] = [dbo].[ DM ].[FCName]),
[DNameCat], [DWeb]
FROM [dbo].[DM]

i am getting error:

Subquery returned more than 1 value. This is not permitted when the subquery follows =, !=, <, <= , >, >= or when the subquery is used as an expression.

My query is: The First Two insert works fine for DCat and Fcat