Construction of a Band reject filter
It sounds like you are looking for what hi-fi designers would call a bass and treble shelving filter. This is made from two parallel circuits sharing the same input source with there outputs summed together: -



Picture taken from this page. Scroll down to the section called 6.1 Shelving Filters with Operational Amplifiers.

There is also this page produced by Elliot Sound Products that describes various filters (including shelving filters) in some detail.