The word twikent (twice-kenned) is used for once-removed metalepsis involving kennings. If a kenning has more than three elements, it is said to be rekit ("extended"). Kennings of up to seven elements are recorded in skaldic verse. Snorri Sturluson characterises five-element kennings as an acceptable license but cautions against more extreme constructions:
Níunda er þat at reka til hinnar fimtu kenningar, er ór ættum er ef lengra er rekit; en þótt þat finnisk í fornskálda verka, þá látum vér þat nú ónýtt. "The ninth [license] is extending a kenning to the fifth determinant, but it is out of proportion if it is extended further. Even if it can be found in the works of ancient poets, we no longer tolerate it." -- Snorri Sturluson
nausta blakks hlé-mána gífrs drífu gim-slöngvir "fire-brandisher of blizzard of ogress of protection-moon of steed of boat-shed" -- from the Hafgerðingadrápa, by Þórður Sjáreksson (this is the longest kenning found in skaldic poetry; it simply means "warrior")
For the nature of metalepsis is that it is an intermediate step, as it were, to that which is metaphorically expressed, signifying nothing in itself, but affording a passage to something. It is a trope that we give the impression of being acquainted with rather than one that we actually ever need. -- Quintilian
But the sense is much altered & the hearer's conceit strangely entangled by the figure Metalepsis, which I call the farfet, as when we had rather fetch a word a great way off than to use one nearer hand to express the matter as well and plainer. -- George Puttenham
Perhaps the most common example of metalepsis in narrative occurs when a narrator intrudes upon another world being narrated. In general, narratorial metalepsis arises most often when an omniscient or external narrator begins to interact directly with the events being narrated, especially if the narrator is separated in space and time from these events.
There are so many examples of forking-path and metaleptic narratives by now that any recommendations will have to seem arbitrary. One of the most thoroughly enjoyable constructions of enigmatic worlds within worlds is Nabokov's Pale Fire (1962). A good short text is Robert Coover's The Babysitter (1969). In film, a frequently referenced forking-path narrative is Peter Howitt's Sliding Doors (1998).
[In Tom] Stoppard's The Real Inspector Hound, the framing diegetic situation is here equally a theatre. In this fictional theatre a whodunnit is performed, witnessed by an audience which includes two theatre critics. In the course of the embedded performance these critics become paradoxically involved in the hypodiegetic play within a play, an involvement which even leads to the death of one of them. Thus, as in the case of Pirandello's Sei personaggi, the typical traits of a metalepsis can here also be recognized: a fictional representation consisting of several distinct worlds and levels, among which unorthodox transgression occur.