Thank you for contacting us and for using Braph for your analysis.
The betweenness centrality in Braph has to option to provide both normalized and unnormalized values when used from the command line. However, if you are using the GUIs provided by Braph, then the default value is the normalized version.
The measure is normalized by the number of nodes. In particular,
BC_normalized = BC_unnormalized / ((N-1)*(N-2)),
where N is the number of nodes in the network.
Hope this helps. Please let me know if can do anything else to help.