Select from stored procedure
This should do what you need.

DECLARE @Id INT

create table #tmpXmlreturn
(
    Data xml,
)

create table #Ids(
    Id int
)

INSERT INTO #Ids
select dbo.Workers.Id as Id
from dbo.Workers

WHILE EXISTS(SELECT * FROM #Ids)
BEGIN
  SELECT TOP 1 @Id = Id FROM #Ids  

  INSERT INTO #tmpXmlreturn
  Exec dbo.GetBranchByWorkerId @Id

  DELETE FROM #Ids WHERE Id = @Id
END

SELECT * FROM #tmpXmlreturn
DROP TABLE #tmpXmlreturn