denoise signal with varied frequency range

I have a question about signal processing. I need to denoise the data of a sensor. I need to have a specific frequency range at any specific times. This specific frequency range varies at different times. How can this be done? The spectrogram photo of sensor data are also attached.

The data for the yellow part should remain and the data for the green part should remove.

Answer 1

[Star Strider]

I doubt that a frequency-selective filter would be possible for a time-varying frequency range. Experiment with the Savitzky-Golay filter (sgolayfilt) for the filtering (I usually use a 3-degree polynomial and vary the frame length until I get the result I want), as well as simple amplitude thresholding, since there appears to be at least a 20 dB difference between the signal and the noise.