Here is an example with a built-in dataset
library(dplyr)
iris %>%
select(contains("Len")) %>%
head()
#> Sepal.Length Petal.Length
#> 1 5.1 1.4
#> 2 4.9 1.4
#> 3 4.7 1.3
#> 4 4.6 1.5
#> 5 5.0 1.4
#> 6 5.4 1.7
Created on 2020-06-05 by the reprex package (v0.3.0)
If you need more specific help, please provide a proper REPRoducible EXample (reprex) illustrating your issue.