I don't see any problem doing that.
Something like following should work.
Your first view
CREATE VIEW [TestView1]
AS
SELECT 1 AS Id, 'Test 1' AS Value
UNION
SELECT 2,'Test 2'
GO
OUTPUT 1
Id Value
______________
1 Test 1
2 Test 2
Your second view
CREATE VIEW [TestView2]
AS
SELECT 1 AS Id, 'Test 3' AS Value
UNION
SELECT 2,'Test 4'
GO
OUTPUT 2
Id Value
______________
1 Test 3
2 Test 4
Your third view
CREATE VIEW [TestView3]
AS
SELECT Value FROM TestView1
UNION
SELECT Value FROM TestView2
GO
OUTPUT 3
Value
______
Test 1
Test 2
Test 3
Test 4
There is no need to apply INNER JOIN which is there for some other purposes.
Hope, it helps :)
In case this doesn't resolve your problem, please let me know.