Field help (UTIFCYFIN) 

Only the account postings entered in the sites where the code is less than or equal to this end range will be selected.
If this field is empty, there will be no control.
The site must belong to the company to which the bank is attached.
If a site is defined in the bank record, then the entry of the site range is prohibited. Only the account postings entered in the site for the bank will be selected.

NB : The account posting selection is simple and only concerns the postings passed in the company for the bank.