Determine the document flow to the sales order

The following function modules:

Document flow similar to VA03:

RV_DOCUMENT_FLOW

Preceding document flow

SD_VIEW_VBFAVG

Subsequent document flow:

RV_FLOW

Furthermore, the following fields in the following tables:

Q-message: VBAK-QMNUM, QMEL_QMNUM read with QMEL-LS_VBELN