These would have to be joined from another OID browsing the UnDP 32bit application on the Solarwinds server.
Juniper unfortunately from experience don't tie things together as nicely as some other vendors.
By the look at your results you're obviously clustered - or just a very large device with multiple engines / SPU's avail
Most times a SNMP query from CLI / UnDP App will resolve by trimming the current OID tree back/looking down another branch.
Within the SRX itself [CLI] you should be able to determin which SPU relates to which index table.
188.8.131.52.4.1.26184.108.40.206.220.127.116.11.11 tells you which row relates to which NodeDescription within your SRX Cluster
So it's just a matter of now getting those 2 results onto the device view.
You should be able to modify the current UnDP view you have to include the other so it reflicts correctly.