https://askubuntu.com/questions/967022/how-do-i-disable-search-as-you-type-text-in-ubuntu-17-10-and-later

# Create your work directory and go there
mkdir bld-nautilus-typeahead ; cd bld-nautilus-typeahead

# Clone the repository holding the needed patch: 
git clone https://git.sequentialread.com/forest/nautilus-typeahead.git
git checkout forest-ubuntu-18.04

# Make sure the source repositories for the main archives are available:
sudo nano /etc/apt/sources.list

# If the deb-src line for the main repository (usually around line 6)   
# is commented out (starts with a #)     
# uncomment it (remove the #) and save the file.  
sudo apt-get update

# Install the build dependencies
sudo apt-get build-dep nautilus

# Retrieve the sources for Nautilus
apt-get source nautilus

# Source should now be in the 'nautilus-3.26.0/' folder. Go there
cd nautilus-3.26.4/

# and Apply the patch from arch-linux
patch -p1 < ../nautilus-typeahead/nautilus-restore-typeahead1.patch

# Build the package from source
dpkg-buildpackage -rfakeroot -uc -b

# This will take a little time. If everything goes well, the related packages will end up in the parent directory. Go there
cd ..

sudo dpkg -i libnautilus-extension1a_3.26.4-0~ubuntu18.04.3_amd64.deb nautilus_3.26.4-0~ubuntu18.04.3_amd64.deb nautilus-data_3.26.4-0~ubuntu18.04.3_all.deb