Decompose graphs into their biconnected components. Graphviz filters:
acyclic,bcomps,comps,edgepaint,gvcolor,gvpack,mingle,nop,sccmap,tred, &unflatten. More information: https://graphviz.org/pdf/bcomps.1.pdf.
bcomps {{path/to/input1.gv path/to/input2.gv ...}} > {{path/to/output.gv}}
bcomps -v -s {{path/to/input1.gv path/to/input2.gv ...}}
output.gv:bcomps -x -o {{path/to/output.gv}} {{path/to/input1.gv path/to/input2.gv ...}}
bcomps -?