The Poisson-Lie T -plurality is an equivalence of string theories on various cosets D/ G, D/ G′ , • • • , where D is a Drinfel'd double and G, G′ , • • • are maximal isotropic subgroups. This can be extended to the equivalence for dressing cosets, i.e., F \D/ G, F \D/ G′ , • • • , where F is an isotropic subgroup of D. We explore this extended Poisson-Lie T -plurality, making the relation between several previous approaches clear. We propose a gauged sigma model for a general gauge group F and obtain the formula for the metric and the B-field on the dressing coset. Using this formula and an ansatz for the dilaton, we show that the Poisson-Lie T -plurality for dressing cosets (with spectator fields) is a symmetry of double field theory. The formula for the R-R field strength is also proposed such that the equations of motion for the NS-NS fields are transformed covariantly. In addition, we provide specific examples of the PL T -plurality for dressing cosets.