During their soft state edge-on black hole transients show blue-shifted absorption lines in their X-ray spectra due to hot and equatorial disk winds. Blue-shifted absorption lines have also been discovered in optical and ultraviolet(UV). These features must be produced in an outflow, but the physical conditions required to form them are very different. The three feautures have never been observed at the same time. It is unclear if they are linked to distinct outflows or simply with different regions. We propose to answer this question with simultaneous time-resolved spectroscopy of a high-inclination soft-state system in the X-ray, UV and optical bands. This will allow us to test if the three types of wind features are present simultaneously and whether they display correlated variability.