The two Index Seek (highlighted in green and red) are for filtering, they did not group in Query Columns tab. But the two Object3 highlighted in red are grouped together instead. Here is the XML Plan.
Does anyone has idea about why PE group the two Object3 highlighted in red and leave the Object3 highlighted in green in another group. I'm sorry asking such a stupid question, because I am a newbie in SQL tuning.
Here is the "Query Columns" tab I am talking about. Plan Explorer grouped the Index Seek and Index Scan. Actually, Plan Explorer will group Index Seek/Scan and Key/RID Lookup together. In this case, I understand the purpose. It help us considering adding the lookup column as an INCLUDE column to an index.
But I don't understand the purpose behind why PE grouped the highlighted Index Seek and Index Scan together!