Representing data flows across systems

[#1]

I am looking at representing a source and destination relation in a systems landscape.
Some sample data flows across systems are as below. It does not seem to be a hierarchy in its true sense.
A-->B
B-->C
C-->A
A<->D
D-->B

In terms of data I have the following tables:
I have SYSTEMS represented as

Sys_ID	Sys_Name
A	aaaa
B	bbbb
C	cccc
D	dddd

Then I have the INTERFACES as:

Interface_ID	Source_Sys_ID	Destination_Sys_ID
11	A	B
22	B	C
33	C	A
44	A	D
44	D	A
55	D	B

How would I be able to show the Sys_ID and Sys_Name as fields and then in a table the Source and Destination's Sys_ID and corresponding Sys_Names?
When I click a Sys_ID it shows the sources and destinations for it. Now if I click a source/destination Sys_ID, the data shown should change to this Sys_ID including the source and destinations for it.

Any ideas pointing in the right direction would be helpful. Thanks in advance.

[Gysbert_Wassenaar]

Try using the CrossTable function:

Interfaces:

CrossTable(SourceDestination, Sys_ID)

LOAD

     Interface_ID,

     Source_Sys_ID as Source,

     Destination_Sys_ID as Destination

FROM INTERFACES;

See attached example.