Hypernymic term for specialization and generalization

Derivative is not a hypernym of specialization and generalization.

Hyponym (Wikipedia)

In linguistics, a hyponym (from Greek hupó, "under" and ónoma, "name") is a word or phrase whose semantic field is included within that of another word, its hyperonym or hypernym (from Greek hupér, "over" and ónoma, "name").

In simpler terms, a hyponym shares a type-of relationship with its hypernym. For example, pigeon, crow, eagle and seagull are all hyponyms of bird (their hyperonym); which, in turn, is a hyponym of animal.

Specialization and generalization do not share a semantic field with derivative.

Semantic field (Wikipedia)

In linguistics, a semantic field is a set of words grouped semantically (by meaning) that refers to a specific subject.

Another example would be colour. Colour is a hypernym of red and blue.

The meanings of the words you have enquired about:

Specialization (Cambridge)

A particular area of knowledge or the process of becoming an expert in a particular area.

Generalization (Cambridge),

Is altogether different semantically:

A written or spoken statement in which you say or write that something is true all of the time when it is only true some of the time.

Specialization is specifically to do with knowledge as a field of study, whereas generalization is to do with an extrapolation of truth from a narrow scope to a wider scope.

However, there are similar words... which do share a hypernym:

Specialist (Collins)

A specialist is a person who has a particular skill or knows a lot about a particular subject.

Generalist (Collins)

A person who is knowledgeable in many fields of study

A hypernym for specialist and generalist would be scope of knowledge.

Consider subsumption.

A subsumption relation in category theory, semantic networks and linguistics, also known as a "hyponym-hypernym relationship" (Is-a) - wikipedia disambiguation page for subsumption

A subsumptive containment hierarchy is a classification of object classes from the general to the specific. Other names for this type of hierarchy are "taxonomic hierarchy" and "IS-A hierarchy". - wikipedia

The natural sense of the term is derived from the word subsume. While the verb is biased towards generalisation, the noun subsumption can be used for relations in both directions. In particular, both generalisation and specialisation are subsumption relations.

subsume verb Include or absorb (something) in something else. ‘most of these phenomena can be subsumed under two broad categories’ - ODO