Fields such as "Actual Cost" and "Forecast Cost" are available to be used in the Hierarchies of the Modern UX, and also in Project Grid, etc. However, even when there is data against an investment / project, these fields do not display any data.
Version: 16.0.1 and above.
The "Post Actuals to Investment" job has to be run to obtain this data in the Modern UX.
Documentation of the job: