In PLAXIS Input, the default behaviour is to store only the last calculation step of each phase. The option to set the Max number of steps stored can be found in Phases window, under the Numerical control parameters.
This parameter defines the number of steps of a calculation phase to be stored.

In case that the Max number of steps stored is larger than 1, intermediate steps are automatically stored depending on the type of calculation as shown in Phases window.

The intermediate steps stored can be inspected in PLAXIS Output, as explained in the article Inspect intermediate step results in PLAXIS Output. Also, these stored steps can be used when generating curves using post-calc nodes (Selecting points for curves article).

For more information on this property, check the Plaxis Reference manual.