In general the mapping file contains nodes and edges only. Fields/InfoObjects of entities which are not mapped are not found in that file. They will be found in the buildup file.
TODO: Mapping with FBPA as source: only Master Data and Facts Semantic is used.
In the mappings file we will not find any Transformation. All Mappings are displayed without a Transformation. 
Will by changed! TODO Alexander Dürrstein
That means if a source entity 1 is connected via transformation to a source entity 2 where field 1 is mapped to field 2, the mapping file contains only one edge like
source="FIELD1|sourceEntity1|<type>" target="FIELD2|sourceEntity2|<type>"
<?xml version="1.0" encoding="utf-8"?> <graphml xmlns="http://graphml.graphdrawing.org/xmlns"> <graph id="G" edgedefault="directed" parse.nodes="5" parse.edges="4" parse.order="nodesfirst" parse.nodeids="free" parse.edgeids="free"> <node id="0MATERIAL|ZPURV01|HCPR" /> <node id="MATNR|ZPURDW11|ADSO" /> <node id="0MATERIAL|ZPURDW12|ADSO" /> <node id="0MATERIAL|ZPURDW22|ADSO" /> <node id="0MATERIAL|ZPURAL01|ALVL" /> <edge id="1" source="MATNR|ZPURDW11|ADSO" target="0MATERIAL|ZPURV01|HCPR" /> <edge id="2" source="0MATERIAL|ZPURDW12|ADSO" target="0MATERIAL|ZPURV01|HCPR" /> <edge id="3" source="0MATERIAL|ZPURDW22|ADSO" target="0MATERIAL|ZPURV01|HCPR" /> <edge id="4" source="0MATERIAL|ZPURV01|HCPR" target="0MATERIAL|ZPURAL01|ALVL" /> </graph> </graphml>