What is the ruling on working in a supermarket that sells both permissible (halal) and prohibited (haram) items, while limiting one's work to only arranging and serving the permissible (halal) goods?

A Muslim should not work for disbelievers in professions considered lowly, as they involve degradation. However, if a Muslim is compelled to do so, there is no sin upon them, as long as they do not sell forbidden things or assist in their sale. It is more prudent to avoid cleaning places where forbidden things are sold by requesting their exclusion in the contract, as this might fall under assisting in their sale by preparing the place. Leaving such a job and seeking another is safer and more absolving for one's conscience, for "whoever avoids doubtful matters has absolved his religion and his honor, and whoever falls into doubtful matters falls into the forbidden." And "And whoever fears Allah – He will make for him a way out and will provide for him from where he does not expect."