It isn't clear what you mean by "derived from". For example "father" and "paternal" historically derive from the same root in proto-Indo European, but in English there is no derivational relationship between these words. Words that are related in that sense of "derive from" are referred to as "cognates" (e.g. "these words are all cognate(s)"). The term generally refers to related words across languages (so would include Sanskrit, German, Slavic and so on), but you can talk about the set of words in English that are cognates, thus father, paternal but not πατηρ.
In terms of synchronic notions of "derive from", where e.g. "digging" and "digs" are derived from the same stem, the term "paradigm" is used to cover the relationship, so the set of words morphologically derived from a given stem would be the paradigm of that stem. One can further subdivide paradigms into sub-types, like derivational vs. inflectional paradigms.
It looks like you're talking about derivational paradigms. However, it is dubious that there is a synchronic relation between your specific examples – there isn't a clear rule-governed relation between the specific forms. There are a number of nouns derived from verbs that add -ion, but the form and meaning of those words is too disparate to be subsumed under any rule (see for example rebel, rebellion; repel, repulsion; divide, division; unite, union; torque, torsion; cite, citation). We generally consider such sets of words to not be synchronically related. Which suggests that you are interested in historical relations, not synchronic morphological ones.
The concept of "cognate" in historical linguistics generally refers to the entire set of words having a common source, so the set of English words that are in this cognate set would include agent, agitate, agony, pedagogue, axiom and a number of other words. You could narrow down the set of words covered by the concept "cognate" by specifying for example "coming from Latin" or "coming from the Latin past participle". There is no single term that would cover exactly the words that you are interested in, at least based on your examples.