the view object will contain the view's name and the view's pipeline.

{
    view: {
        name: <name of view>,
        effectivePipeline: <pipeline>
}

The effective pipeline being the current view's pipeline + any ancestor view pipelines. 

So if view A is 

{$addFields : {a: <...>}}

and view B is created on top of A and its pipeline is

{$addFields: {b: ...}}

, then the effective pipeline for createSearchIndex on B would be 

[{$addFields: {a: <...>}}, {$addFields: {b: <...>}}]

The effective pipeline is only required for the createSearchIndex command. But the nesting the view's name as 

{view: {name: <...>}}

 is required for all search index commands