This post gives a detailed guide to copy specific text from SMS or copy full SMS text in Xiaomi (Redmi, MI) phones.
Copy specific text from SMS in Xiaomi phones
To copy specific text from SMS, first open SMS in the message app and double tap on SMS text. Next, long press on specific text to open the copy option. Now, copy text and paste where you want.
Copy full SMS text from in Xiaomi phones
To copy full SMS text in Xiaomi phones, first open SMS in the message app and long press the sms content. Now, you can copy the full message using options and paste where you want.