Hierarchy no. & for sender smaller than/equal to that for receiver &

What causes this issue?

You are settling several objects in one run. In the process, some of
these objects receive values from other objects in the same settlement
run.
To ensure that all the objects in a settlement run are settled to zero,
you must settle the objects in a particular order. You do this by
assigning hierarchy numbers from 0 to 999.
,,Example:
In a settlement run, order 1 is settled to order 2. Order 2 is in turn
settled to order 3.
You must settle order 1 first, then order 2 (with the debits arising
from the settlement of order 1), and finally order 3 (with the debits
from the settlement of order 1 and order 2).
This means that order 1 must have the highest hierarchy number, order 2
a lower one, and order 3 the lowest - e.g. 300, 200, 100.

System Response

This message is only a warning. You can still save your orders without
amending the hierarchy numbers. However, it may then be the case that
not all objects are settled to zero in one run. You may then have to
start settlement more than once.

How to fix this error?

In simple cases, the system adapts the hierarchy number for the sender.
In other cases, you need to adapt it.
Use the "Settlement hierarchy" function key to display an overview of
which sender settles to which receiver. You can also display the
hierarchy numbers that have associated objects. You can use this to
check whether a loop has occurred. For example, order 1 -> order 2 ->
order 3 -> order 1.

Error message extract from SAP system. Copyright SAP SE.