The phrase "action is split" is correct and usable in written English.
It can be used in contexts where an action or process is divided into different parts or segments.
Example: "In the film, the action is split between two main characters, each facing their own challenges."
Alternatives: "action is divided" or "action is segmented".
The action is split across two different audio channels.
The action is split into five acts, each culminating in a boss battle.
The action is split between the mythic world and the sitting room of Sigmund Freud, who is psychoanalyzing the title character.
As in Assassin's Creed II, the action is split between the near-future and the early 15th century, as Desmond Miles explores his genetic memory through a virtual reality interface known as the Animus.
In season three the action is split between two new settings: the abandoned prison Rick Andrew Lincolnn) is holed up in and the zombie-proof gated community of Woodbury run by the villainous governor (David Morrissey), who is so evil he makes the undead seem cuddly.
When the curtain rises on Katie Mitchell's revival of Thomas Heywood's 1603 drama of property and marriage, adultery and revenge, it looks as if we might be in for one of those Alan Ayckbourn comedies where the action is split between two separate places, both of which are in constant view.
The tsunami's action was split into 2 parts: (1) the first impact of solitons was tested by means of large solitary waves and, (2) the subsequent overflow was approached by applying a pump-driven wave maker.
The action of the video is split between virtual and real space, seeming to probe at the human compulsion to explore digital realms and our, often, reluctance to return.
In particular, the sense of disownership seems to be nicely explained by the lack of bodily control "The body is a unity of actions, and if a part of the body is split off from action, it becomes 'alien' and not felt as part of the body" (Sacks, 1984, p. 166).
Just as at its former occupant, Kenmare, the late-night action takes place downstairs, which is split between a 25-seat cocktail bar and the just-opened Stardust Lounge, a tiny karaoke club whose Tokyo kitsch will probably populate your Instagram feed this fall.
The team's work is split between action-packed "operativos" and time spent tapping on computers in what is supposed to be the Mexican federal police intelligence center but which looks more like a neon-lighted conference room in a 1960s Acapulco hotel, only with much snazzier electronics.
