Visualize connections between vertices given a vertex data

I have several triangle meshes, and, for each vertex of the mesh, I have a list of other vertices, with an unknown number of elements, which basically represents a sparse matrix of connectivity.

I would like to know how I can store this data as vertex data of a VTKUnstructuredGrid, or any other mechanism to store the data.

Also, I have no clue how I could visualize, for a given vertex, the vertices that are related. I have thought about creating a filter which takes as input the data, as parameter the vertex I want to analyze and draws segments to the other vertices. Is there something similar available in paraview?