Report in MSSSRS without Star Schema?
It sounds like you are talking about creating a report that allows the users to choose the grouping of the data, e.g. there is a report parameter that allows the user to select "Employee", "Department" etc. which will then drive the grouping in the report data (presumably a table).

You have a couple of options to achieve this:

1) Create a dataset that uses dynamic SQL to build the query selected columns and GROUP BY clause based on the user's selection. This is probably the best performing option but in my experience is more trouble than it's worth due to the inherent difficulties of debugging or changing dynamically built SQL statements.

2) Create a dataset that contains all the possible grouping columns using a simple select statement, and then design the report to dynamically group the results based on the user selection. In your case this is the simplest choice since your data is already in a single table.

e.g. if you have a report parameter called "GroupBy", then you can set the grouping expression in the report data region (e.g. a table) to:

=Fields(Parameters!GroupBy.Value).Value


So if one of the dataset columns is called "Employee" then you need a parameter option with a value of "Employee". If the user selects this parameter option then the table grouping is set to employee. You also need to use a similar expression to set the display value in the grouping column (e.g. if the grouping is by Employee, then you need to display the Employee name).