list manipulation - How to constrain the generation of all possible orderings?

Here is code from Simon Woods' answer for getting all possible weak (equal ranks allowed) orderings for $N=3$ objects:

 ClearAll[f]; SetAttributes[f, Orderless];
 ReplaceList[f[a, b, c], f[a___, b___, c___] :> {{a}, {b}, {c}}] //
 DeleteCases[#, {}, -1] & // Union // Column

It gives $13$ such orderings:

{{a, b, c}}

{{a}, {b, c}}
{{b}, {a, c}}
{{c}, {a, b}}
{{a, b}, {c}}
{{a, c}, {b}}
{{b, c}, {a}}
{{a}, {b}, {c}}
{{a}, {c}, {b}}
{{b}, {a}, {c}}
{{b}, {c}, {a}}

{{c}, {a}, {b}}
{{c}, {b}, {a}}

How can I modify this code for the case when not more than $2$ subsets are allowed? The desired output is:

{{a, b, c}}
{{a}, {b, c}}
{{b}, {a, c}}
{{c}, {a, b}}
{{a, b}, {c}}
{{a, c}, {b}}

{{b, c}, {a}}

I am trying to find way for doing such reductions in general $N$ and for any number of subsets-restriction.

Answer

Here's how you can generalize the code for any $N$:

ClearAll@weakOrderings
weakOrderings[list_, n_Integer] := 
    Block[{f, x = Table[Unique["x"], {n}]},
        SetAttributes[f, Orderless];
        With[{lhs = f @@ (Pattern[#, BlankNullSequence[]] & /@ x), rhs = List /@ x},

            ReplaceList[f @@ list, lhs :> rhs] // DeleteCases[#, {}, -1] & // Union // Column
        ]
    ]

You can verify that it gives you the expected results: