Virginia has tax reciprocity with both MD and DC with regard to W-2 income. That means that your work income from MD and DC is taxable only by your resident state of VA.
If your employer incorrectly withheld DC taxes, you should file DC Form D-40B in order to obtain a refund. It is not necessary to file a DC tax return. Here's a link to the 2022 form; the 2023 form has not yet been published.
https://otr.cfo.dc.gov/sites/default/files/dc/sites/otr/publication/attachments/2022_D-40B.pdf
You should also file DC Form D-4A with your DC employer to stop the DC withholding.
https://otr.cfo.dc.gov/sites/default/files/dc/sites/otr/publication/attachments/2018%20D-4A.pdf
If your employer is based in MD, file MD Form MW507 with them in order to stop the MD withholding.
https://www.marylandtaxes.gov/forms/current_forms/mw507.pdf
To obtain a refund of incorrectly withheld MD taxes from MD, as @ee-ea said you'll have to file a non-resident MD tax return on which you show the withholding but declare zero MD income.
**Answers are correct to the best of my ability but do not constitute tax or legal advice.
