How to further breakdown trend contribution

I'm building a time-series forecasting model to forecast Sales. The model is trained with additional regressors like weather, promotions, distribution points. When calculating the feature impact on sales, I see that trend is the most driving feature (like 80% of the sales) and rest of the regressors and seasonality is 10%.

I want to breakdown this trend component into multiple components, what can this be breakdown into and how to do it.