How to select values that have specific characters

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.