These will be used to pass as prompt values in your DLR.
For ex say, you have oracle db as source, then you can filter certain records which has some specific name, like say Asset for 1 DLR and Liability for another DLR to load to target (Asset to one target and Liability to another target) and then you can use these parameters and give Asset & Liability in your DLR for target load.
In summary using the ODI studio you can create a new variable p_entity_list, set it as a refreshing variable, you will see what you need to enter for the select query if you look at other variables.
Add a new filter to interface "ERPI Open Interface to ERPI Balances" against the column you want to filter and put the variable in the clause, add the variable into the package "Open Interface Balances" and set it as a refresh variable.
In the import format regenerate the scenario, enter a value in the rule for p_entity_list and run the rule.