how do I join two complex Statements with different number of targets

[mcelrob5]

I am working on a SQL statement the works on relationships mapped amongst software and hardware.

The result I am looking for from the following statement should look like this: (the example table is in code style for formatting purposes)

-----------------------------------------------
| App Name | Server | Environment | DR Server |
-----------------------------------------------
| App1     | svr1   | Env1        | svr3      |
| App1     | svr2   | Env2        |           |
.
.
.

The result should contain all
Environment -> Server -> App
relationships in the table and if the server has a DR Server associated with it it should be list

In the SQL statement below the first select grabs all the Servers with a DR Server mapped to it and the second select grabs the rest of the relationships without a DR Server mapped to it. Here is my code:

select a.[ApplicationName] as [App], a.[RelationshipValue1] as [Server],
		a.[RelationshipValue2] as [Environment], c.[RelationshipValue1] as [DR Server]
from Relationship_Table a, Relationship_Table b, Relationship_Table c
where (a.[ApplicationName] = 'ACE' and b.[ApplicationName] = 'ACE' and c.[ApplicationName] = 'ACE')
		and (a.[RelationshipType] = 'Environment --> Server' and b.[RelationshipType] = 'Environment --> Server'
			and c.[RelationshipType] = 'DR Server --> Production Server') 
		and (a.[RelationshipValue2] != 'DR' and b.[RelationshipValue2] = 'DR') 
		and (b.[RelationshipValue1] = c.[RelationshipValue1] and a.[RelationshipValue1] = c.[RelationshipValue2])
		and (a.[IsDeleted] = 'N' and b.[IsDeleted] = 'N' and c.[IsDeleted] = 'N')
UNION
select d.[ApplicationName] as [App], d.[] as [Server],
	d.[RelationshipValue2] as [Environment]
from Relationship_Table d
where d.[ApplicationName] = 'ACE' and d.[RelationshipType] = 'Environment --> Server' 
	and d.[IsDeleted] = 'N'

Can anyone help me with a similar example whether it is original or can be viewed on a site?