SQL Server group、筛选和合并列，只显示一行

I have a table that grows vertically with properties. I am using PIVOT to convert the rows values into columns and get required data. Now, I am trying to concatenate the values stored in two separate rows based on some filter. After concatenation, I just need to show one row out of this group and second row's id column should go as new column in the resultset.I have a table that grows vertically with prope