For line item report FBL1N/FBL3N/FBL5N, people usually want to select by some other criteria, such as by line item text.
Solution:
SE36: Edit logistical table. SDF for FBL3N, KDF for FBL1N , DDF for FBL5N.
select: Extra -> select views.
Copy SAP -> CUS.
Then change CUS.
Double click the table on top right , then assign the function group to the field you want for dynamic selection.
