rosbag loading specific messages

I am curious if there's a better way to load information from ROS bag files.

My current work flow is:

bag = rosbag(FILE_LOCATION)
bagSel = select(bag,'Topic','/mavros/imu/data')
X_imu_raw = timeseries(bagSel)

t_imu_angvel = X_imu_raw.Time - bag.StartTime
X_imu_angvel = X_immu_raw.Data(:,8:10) % problem line

When having to load a lot of different message sets this becomes very cumbersome. I'm not sure how to pull sets of messages from the timerseries, for example I could write:

timeseries(bagSel,'AngularVelocity.X')

and it will return the angular velocity around the X axis. I would ideally like to write something like:

timeseries(bagSel,'AngularVelocity')

and pull all of the angular velocity messages from the topic (x,y, and z) but i'm not sure if it is possible nor how to do it?