Hola Jie,
This is a good question. While it is not possible to reconstruct multiple time series using a subset of the original data, you could consider using Principal Component Analysis (PCA / SVD) to reduce the dimensionality of the data, then use that subset of its principal components to reconstruct the data in a way that closely resembles the original multiple time series data.
Here is "Principal Component Analysis (PCA): A Step-by-Step Explanation" that speaks broadly about PCA -- https://builtin.com/data-science/step-step-explanation-principal-component-analysis -- as well as "PCA Using Python: A Tutorial," a tutorial that runs you through a basic example of using PCA to find the principal components of the well-known "Iris" dataset -- https://builtin.com/machine-learning/pca-in-python --
Look forward to hearing how that goes!